The present invention relates to a wet process with no heating for continuous transfer pattern printing of a cellulose fabric web and its blends, and in particular to a wet process with no heating for continuous transfer pattern printing of a cellulose fabric web and its blends by using a corona-treated plastic film as a pattern carrier web and a dye admixed with a thickening agent containing water-soluble and alcohol-soluble hydroxypropyl cellulose or polyvinyl pyrrolidone as ink.
Printing on textile webs can be classified into direct textile printing and indirect textile printing. What is called indirect textile printing is transfer pattern printing. A disadvantage of direct textile printing is that before the patterns are set to their correct positions for printing, a substantial amount of textile web must be used, and the patterns are difficult to set in their correct positions, thereby causing the loss of the textile webs. Another disadvantage of direct textile printing is that manufacturers have to produce quite large supplies of the individual designs, and if the designs of the patterns go out of fashion, the stock of designs will increase. Also, as a plurality of screens are used in direct textile printing, patterns of different color tones, for example, pattern of half color tone can not be obtained.
For transfer pattern printing, however, patterns are first printed on a pattern carrier web, and then transferred to the textile web. Therefore, transfer pattern printing has the advantages over direct textile printing that the loss of textile web is small, and it is possible to obtain a quite sharp transfer of the patterns. Furthermore, as the pattern carrier web is much cheaper than the textile web, if the patterns go out of fashion, this will only cause an increase of the stock of cheap pattern carrier web. Also, by using transfer pattern printing, the users only need equipment for transfer pattern printing, and no investment in a factory, equipment or people for manufacturing plates is needed. In addition, transfer pattern printing utilizes intaglio, thus, only one station can print patterns of different colortones.
U.S. Pat. No. 3,666,397 discloses a transfer printing process wherein a cellulose fabric web is kept in contact, in the wet state, with a support heated to 100 .degree.to 106.degree. C. for 0.5 to 220 seconds. The process has the disadvantage that the cellulose fabric should be impregnated with an alkali solution, but this step makes the impregnated cellulose fabric become yellowish in the subsequent heating step, if the heating is too long or is effected at an elevated temperature.
U.S. Pat. No. 5,196,030 discloses a continuous process with no heating for transfer pattern printing. In other words, according to said process, transfer pattern printing on cellulose fabric, such as cotton, can be conducted at a low temperature. However, absorbent paper webs having an air permeability of 0.1 to 3,000 nm/Pa.s as measured according to standard test method SCAN P 26:78 and having a water absorption corresponding to a Cobb number below 50 as measured according to standard test method ISO 535, 1976 must be used as the pattern carrier web. Therefore, the source of such pattern carrier web is not readily available, and thus the process is still not satisfactory. Also, before the absorbent paper webs are printed with a pattern of dyestuff, they must be coated with carboxy methyl cellulose (CMC), an alginate or an aqueous dispersion of polyethylene or polyacrylate. This step also increases the operations and the cost when the process is to be applied in industries. Moreover, water is used as the dissolving solution for the printing paste in the whole process, and this necessitates a higher drying temperature, such as 100.degree. C., because the drying rate of water is relatively lower than that of other organic solvents.
In addition, sublimation transfer printing is a method of printing textile web by using heat and pressure to transfer disperse dyestuff printed on a pattern carrier web to textile webs of synthetic fibers, for example, polyester fibers. French Patent No. 1,223,330(1958) issued to Filature Prouvost-Masurel has disclosed a sublimation transfer printing method for textile webs of polyester fibers. However, as the disperse dyestuffs used for sublimation transfer printing do not have affinity to a cellulose fabric web or its blends, the printed textile webs have poor fastness to washing, daylight or rubbing.